Monitoring circadian rhythms of individual cells in plants.
Monitoring circadian rhythms of individual cells in plants.
复制标题
监测植物中单个细胞的昼夜节律。
DOI：
10.1007/s10265-017-1001-x
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
T.
中科院分区：
文献类型：
--
作者：
Muranaka;T.;Oyama;T.
生物钟是一种基于细胞自我维持振荡的内源性计时系统。这些细胞生物钟组成了一个多细胞生物钟系统，分别在组织、器官、植物体的各个层次上起作用。然而，在植物中如何协调众多的细胞时钟一直不清楚。由于难以监测完整植物中单个细胞的昼夜节律，因此在单细胞水平上关于昼夜节律钟行为的信息很少。我们以浮萍为材料，研制了一套单细胞生物发光成像系统，并成功地对完整植物的细胞钟行为进行了一周多的观察。这种成像技术定量地揭示了细胞时钟行为的异质性和独立性。此外，这些定量分析揭示了细胞昼夜节律的局部同步，这意味着细胞时钟之间的相位吸引力相互作用。细胞与细胞之间的相互作用看起来太弱，无法在恒定条件下协调细胞时钟对抗它们的异质性。另一方面，在光暗条件下，细胞时钟的异质性似乎是由细胞间的相互作用，使细胞时钟在整个植物水平上表现出明确的空间格局的阶段。因此，人们认为细胞时钟之间的相互作用是一种适应性特征，在昼夜循环下工作，以协调植物体内的细胞时钟。这些发现为理解植物昼夜节律系统的时空结构提供了一个新的视角。
The circadian clock is an endogenous timing system based on the self-sustained oscillation in individual cells. These cellular circadian clocks compose a multicellular circadian system working at respective levels of tissue, organ, plant body. However, how numerous cellular clocks are coordinated within a plant has been unclear. There was little information about behavior of circadian clocks at a single-cell level due to the difficulties in monitoring circadian rhythms of individual cells in an intact plant. We developed a single-cell bioluminescence imaging system using duckweed as the plant material and succeeded in observing behavior of cellular clocks in intact plants for over a week. This imaging technique quantitatively revealed heterogeneous and independent manners of cellular clock behaviors. Furthermore, these quantitative analyses uncovered the local synchronization of cellular circadian rhythms that implied phase-attractive interactions between cellular clocks. The cell-to-cell interaction looked to be too weak to coordinate cellular clocks against their heterogeneity under constant conditions. On the other hand, under light–dark conditions, the heterogeneity of cellular clocks seemed to be corrected by cell-to-cell interactions so that cellular clocks showed a clear spatial pattern of phases at a whole plant level. Thus, it was suggested that the interactions between cellular clocks was an adaptive trait working under day–night cycles to coordinate cellular clocks in a plant body. These findings provide a novel perspective for understanding spatio-temporal architectures in the plant circadian system.